One hundred autopsy eyes, stained with hematoxylin eosin and periodic acid-Schiff were studied by light microscopy. In selected cases other special histochemical stains and enzyme digestion procedures were used. Twelve optic nerve specimens were studied by electron microscopy and stained with uranyl acetate, lead citrate and the modified Thiery Method (PAS-thiosemicarbazide). Corpora amylacea were more common in eyes from older individuals and occurred in 93% of the cases, either in the optic nerve or retina. They measured 2 x 2 micron m in diameter and stained positive for sulphated polysaccharide. By electron microscopy, the deposits were best demonstrated with the modified Thiery stain. Corpora amylacea were intracellular or extracellular structures with randomly oriented, elongated straight, branching 6 micron m thick filaments and a granular electron-dense background. The demonstration of coated vesicles and nematosomes in corpora amylacea are indicative of their neural origin.